Improved experimental test of detailed balance and time reversibility in the reactions /sup 27/Al+parrow-right-left /sup 24/Mg+. cap alpha

A new test of the principle of detailed balance in the nuclear reactions /sup 27/Al(p,..cap alpha../sub 0/) /sup 24/Mg and /sup 24/Mg(..cap alpha..,p/sub 0/) /sup 27/Al at bombarding energies 7.3 MeV< or =E/sub p/< or =7.7 MeV and 10.1 MeV< or =E/sub ..cap alpha../< or =10.5 MeV, respectively, is reported. Measured relative differential cross sections agree within the experimental uncertainty ..delta.. = +- 0.51% and hence are consistent with time-reversal invariance. From this result an upper limit xi< or =5 x 10/sup -4/ (80% confidence) is derived for a possible time-reversal--noninvariant amplitude in the reaction.